Abstract: This paper deals with the time sequences and the heat energy requinement of em bryonic development, morphological characteristics of postembryonic development, and the genomic patterns of gastrulating embryonic cells of maternal fish, Cirrhinus molito rella (mud carp), heterogenic paternal fishes,Sinilabeo decorus tungting, Sinilabeo de corus decorus, and Barbodes denticulatus denticulatus, as well as their hybrids. The dif ference of above mentioned properties between the parental fishes and their hybrids are discussed in relation to the hybridizing incompatibilities. The genetic factors of hy bridizing incompatibility in fishes are clearly pointed out and their related problems are discussed as well.